Ronaldo rescued Corinthians a 1-1 draw with Palmeiras with a fine header from a corner kick which came three minutes into second half injury-time.
The former FIFA World Footballer of the Year started for the first time with the Corinthians shirt, and he made a massive impact.
Not only did Ronaldo give Corinthians a last-gasp draw, but it came against their biggest rivals in a top-of-the-table Paulista State Championship match.
"I couldn't contain my emotion. It was a great feeling," said Ronaldo. "I feel that I can't go wrong in these situations. When I'm in front of goal, finishing is what I know how to do best."
During his goal celebration, Ronaldo jumped onto a fence, which was immediately brought down by delighted Corinthians supporters. Ronaldo was mobbed by his teammates and by the media.
Ronaldo, 32, entered the field in the 63rd minute, and fifteen minutes later he stuck the crossbar with a powerful effort.
He continued to look lively towards the end of the game, and created a couple of good opportunities for his teammates.
Ronaldo marked his return to football in a 2-0 victory over Itumbiari midweek. In this game Ronaldo also made a telling influence.